Add Scope::Container and Scope::Container::DBI
Use Scope::Container::DBI for correct dbh object cache
Change cache duration. process lifetime to coteng object one
Use  for ROOT DBI CLASS interface
Update document
Checking in changes prior to tagging of version 0.10.

Changelog diff is:

diff --git a/Changes b/Changes
index f364e9b..fd125b9 100644
--- a/Changes
+++ b/Changes
@@ -2,6 +2,11 @@ Revision history for Perl extension Coteng

 {{$NEXT}}

+0.10 2014-01-13T06:36:08Z
+
+    - Reintroduce safe cache of dbh object by Scope::Container::DBI
+    - Change $Coteng::CLASS role.
+
 0.09 2014-01-12T03:03:24Z

     - Don't cache dbh object because DBI cannot reconnect when db connection is killed